Parts of a Mushroom Diagram – Cap, Gills, Ring and Cup

All 9 parts on the diagram

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The mushroom 7

Cap The umbrella-shaped top. The gills are on its underside.
Gills Thin plates under the cap. The spores form on them.
Spores A fine powder that falls from the gills and spreads the fungus.
Ring (annulus) What is left of the veil that covered the young gills.
Stem (stipe) It holds the cap up. Also called the stipe or stalk.
Cup (volva) A sack around the foot of the stem, often under the soil.
Mycelium A web of fine threads in the soil. It is the main body of the fungus.

The button 2

Button A young mushroom, shaped like an egg. The cap and stem are already inside.
Universal veil A skin that wraps the whole button. It tears as the mushroom grows.

How this list was compiled: Every name was checked on 2026-09-30 against sources read that day; a name is kept only when two of them use it. (1) USDA Forest Service, Northern Research Station, Field Guide to Common Macrofungi in Eastern Forests and Their Ecosystem Functions, General Technical Report NRS-79, 2011, https://www.nrs.fs.usda.gov/pubs/gtr/gtr_nrs79.pdf (the parts of a mushroom shown on an Amanita: young mushrooms are called buttons or the egg stage and hold the preformed cap and stalk; the cap breaks through the universal veil; the veil over the gills and spores tears and leaves a ring, or annulus, on the stem, also called the stipe or stalk; a cup, or volva, at the stalk's base, often within the soil; patches on the cap are remnants of the universal veil; most of the fungus is an unseen mass of threadlike hyphae). (2) Wikipedia, text only: Mushroom, https://en.wikipedia.org/wiki/Mushroom (a fruiting body of a fungus with a stem or stipe, a cap or pileus and gills; the gills produce spores, which fall as a fine powder from under the cap; a mushroom develops from a button; the universal veil may stay as a cup (volva) at the stalk's base; it grows from mycelium, the mass of threadlike hyphae the fungus is made of; many mushrooms have no universal veil), Universal veil, https://en.wikipedia.org/wiki/Universal_veil , Annulus (mycology), https://en.wikipedia.org/wiki/Annulus_(mycology) , Volva (mycology), https://en.wikipedia.org/wiki/Volva_(mycology) , and Mycelium, https://en.wikipedia.org/wiki/Mycelium . (3) Penn State Extension, Basic Procedures for Agaricus Mushroom Growing, https://extension.psu.edu/basic-procedures-for-agaricus-mushroom-growing (mycelium; pins; cap; the veil). Licence: own work

The drawing: Drawn for this site on 2026-09-30 from plain curves; own work, nothing traced. Licence: own work

How it works

This parts of a mushroom diagram shows a gilled mushroom standing in soil: cap, gills, ring, stem and cup above, and the mycelium below. A mushroom is a fungus, not a plant.

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Above the soil and below it

The mushroom is only the part that makes spores. Most of the fungus is the mycelium, a web of fine threads hidden in the soil. The spores form on the gills under the cap and fall as a fine powder.

Button, veil, ring and cup

A mushroom starts as a button. In some kinds a skin called the universal veil wraps the whole button. As the cap pushes up, the veil tears: its foot stays as the cup, and bits may stay as patches on the cap. A second veil over the gills tears too and leaves the ring.

Not every mushroom has a ring or a cup. Many have no universal veil at all.
The cup often sits under the soil, so it is easy to miss.

Questions and answers

What are the main parts of a mushroom?

A cap, gills under the cap and a stem. Some mushrooms also have a ring on the stem and a cup at its foot. Below the ground is the mycelium, the main body of the fungus.

Is a mushroom a plant?

No. A mushroom is the fruiting body of a fungus. It makes spores, the way a fruit holds seeds, and it grows from a mycelium in the soil or in wood.

What is the ring on a mushroom stem?

It is called the annulus. A thin veil covers the gills of the young mushroom. When the cap opens the veil tears, and what is left hangs on the stem as a ring.

What is the mycelium?

The mass of fine threads, called hyphae, that makes up most of a fungus. It lives out of sight in soil or wood, and mushrooms grow from it.